Electron discharge device



J. 5. DONAL, JR,, ET AL 2,559,604

July 10, 1951 ELECTRON DISCHARGE DEVICE 2 Sheets-Sheet 1 Original FiledMarch 29, 1944 3nventors .4 Je. fieomv Gttorncu Z sw M 1 .m mfiw 501W WJ. S. DONAL, JR, ET AL July 10, 1951 ELECTRON DISCHARGE DEVICE OriginalFiled March 29, 1944 2 Sheets-Sheet 2 12. l? g V Zmventors c/OH/V 5300/1/44 Je. 5420544025 5. ieon/A/ 8 Una/we lay/.9 67/0044 M attorneyPatented July 10, 1951 UNITED STATES PATENT OFFICE ELECTRON DISCHARGEDEVICE Original application March 29, 1944,; Serial No.

528,538. Divided and this application November 10, 1947, Serial No.785,062

8 Claims. (Cl. 250-275) Our invention relates to electron dischargedevices useful at ultra high frequencies, more particularly to devicesof the magnetron type employing cavity resonators.

This application is a division of our copending application Serial No.528,538, flled March 29, 1944, now Patent No. 2,443,445, dated June 15,1948, assigned to the same assignee as the present application.

Magnetrons utilized at ultra high frequencies and employing cavityresonators may be of several types. Those formed from a solid anodeblock have slots extending radially from the central cathode chamber andforming anode seg-:

ments, the slots providing the cavity resonators between adjacent anodesegments. The slots may be enlarged at their inner ends to provideresonators having a circular transverse section. In another type aplurality of slats or fins are supported within a central space andextend radially inwardly toward and define a cathode space, the inneredges of the slats serving as the anode segments and the slats and theirsupporting base providing cavity resonators between the anoderesonators.

In magnetrons of this type, that is multisegment type utilizingresonators, it is desirable to have the magnetron operate in only onemode, several modes being possible. In order to do this,alternatesegments are connected or strapped together by means of conductors toinsure operation in the desired mode. Magnetrons utilized at very highfrequencies are of small size and it is difiicult to strap the anodesegments together. Thus, accurate and reproducible results in strappingare diflicult to accomplish, causing variations in dimensions in thespacing which not only affects the Wavelength at which the magnetronsoperate, but also the efficiency of operation.

It is an object of our invention to provide magnetrons having improvedmethods of strapping, promoting'ease of construction, accuracy andreproducibility as to dimensions and spacings, thus insuring thatmagnetrons of the same size-will operate at the same frequencies and athigh efiiciencies.

The novel features which we believe to be characteristic of ourinvention are set forth with particularity in the appended claims, butthe invention itself will best be understood by" reference to thefollowing description taken in connection with the accompanying drawingin which Figure 1 is a top view with parts removed to show details ofconstruction-of an electron discharge device made according to ourinvention, Figure 2 is a longitudinal section taken along the lineII-II-of Figure 1, Figure 3 is a longitudinal section taken along theline III-11]: of Figure 1, Figgure 4 is an enlarged view of the anodesegments and; showing details of the strapping members employed in thedevice shown in Figures 1, 2 and 3, Figurefi is a perspective showingdetails of construction'of a strapping member made according to ourinvention, Figure 6 is a section taken alongv theline VI-VI of Figure4,- Figure 7 is a sectional view of a modification of the constructionshown in Figure 6, Figures 8 to 13, inclusive, illustrate thesteps inthe construction of another form of strapping arrangement according toour invention, Figures 14 and 15 show details of construction of anelement utilized in Figures 8 to 13, inclusive, Figure 16 is a partialtop View of a modification of the strapping arrangement shown, in Figure4;, Figure 17 is a section taken along the line XVIIXVII of Figure 16,Figure 18 is a partial section showing a modification of theconstruction shown in Figure 17, Figure 19 is a further modification ofa strapping arrangement shown in Figure 16, and Figure 20 is asectiontaken along: the, line XX'XX of Figure 19.

Referring toFigure 1, an electron discharge device employing ourinvention is of themagnetron type and comprises an anode block 2!supporting: a plurality of. radially directed slats or fins 22 whichextend inwardly from said block, the inner ends of the slats providingthe anode segments and defining. the cathode space in which the cathode23 is axially positioned, this cathode being supported by the magneticinsert member M having oppositely disposed thereto a second magneticinsert member 25 which formsv part of the-magnetic circuit completed bya magnet having polesi d and The cathode and inserts are supported bymeans of conducting bridging members-26 and El which are inturninsulatingly supported from the anode block by means of the bolts 28 and29 insulated by means of insulating tubular members 39, 3!, 32 and 33',these bolts also beinginsulated from the block by means of the inserts30' and 32".

This electrode assembly is mounted on header member 35 to which issealed an envelope 36, the header and envelope being made ofnon-magnetic material, for example, stainless steel. The cathode andheater leads 3'! and 38 extend through the header and are sealed thereinby means of the elongated insulating cup-shaped members 3'! -and- 38-.One of the cavity resonators formedbetween the slats 22 has coupledthereto coupling I r 7 2,559,604 r.

slats or anode elements 22 is provided with a slot or recess 55 forreceiving a strapping ring made according to our invention and shown ingreater detail in Figure 5. This strapping ring 46 is provided with aplurality of deformations or extensions t8 normal to the plane of thering which are positioned so that they contact alternate slats as shownin Figure 4. Two such rings are provided, one of which, $1, is ofsmaller diameter than the outer ring 46 and also'being provided withextensions 48 normal to the plane of the strapping ring, thesedeformations engaging and being electrically connected to the othergroup of alternate anode slats. Thus during operation the voltage onadjacent anode segments are in phase opposition. As shown in Figure 6,the ring it is connected to the slat which is spaced from the ring 41and likewise the ring ll is electrically connected at 58' to one of theslats while the other ring 4% is positioned in space with respectthereto;

In the arrangement shown in Figure 7 the slot or recess is in the slats22 is stepped so that the rings are positively positioned with respectto each other, the smaller strapping ring il engaging the inner step andthe outer ring 48 engaging the outer step, lateral movement between therings thereby being prevented.

The embodiments of our invention illustrated in Figs. 1 through 7 areclaimed in our co-pending application referred to above.

In the case of magnetrons formed from a block by means of slotsextending radially from a central chamber, a diiierent approach to theproblem is provided. Referring to Figures 8 to 15, the slots result inthe provision of a plurality of anode segments 5%, the inner ends ofwhich define the cathode space in which is axially mounted the cathode52. In the first step in providing the strapping arrangement, the anodesegments are recessed as indicated at 53. The element 54 shown inFigures 14 and 15 is then positioned as indicated in Figures 19 and 11.This element or spider 54 is in the form of a ring provided with threeprojections or legs 55, the outer portions of which legs are formed toprovide steps 56. Likewise a ring 5! provided with a step 58 ispositioned within the recess 53 in contact with the vertical outer wallof the recess. After being secured in position the ring 51 is out alongthe slots 5! and the portions of the ring 51 on alternate segments onlyare left as indicated in Figure 10, to provide step elements onalternate segments. To provide alternate stepped portions at the innerends of the anode segments 50, the spider 5c is also cut along saidslots so that separate steps 56 are left on alternate segments 59.mounted at the ends of the segments 50 in between those segments inwhich the step elements of the ring 5'! are left. The portions of spider54 left between the legs 55 after the spider is cut provide the innerwalls 54' as shown in Figures 11 and 12. It is now possible to positiontwo concentric strapping rings 59 and 60 within the recess 53, the outerring 59 being mounted on the step elements of the ring 51 and connectingIt is noted that the stepped legs 55 are 4 alternate anode segments andthe inner ring Bl being mounted on the stepped legs 55 of the spider 54,the relationship of the inner and outer strapping rings being shown inFigures 12 and 13. Thus a most accurate positioning of the ringsresults.

Another way of providing the steps 58 is to utilize the laminatedconstruction shown in Figure 20, the first and second laminations 80adjacent the -recess being extended one beyond the other to providesteps on which to place the outer ring 59.

A still further method would be to use a ring having step portions andintermediate portions of less width and then cutting along the slots inthe same manner as is done with the central spider.

A further modification of the strapp n arrangement is shown in Figure16. Here a pair of spiders are utilized, one of the spiders 14 beingprovided with radial extensions or legs l5 so that alternate segments 10between the slots H are connected by this spider. The second spider 12is positioned over the first spider it and the radial legs i3 engage theanode segments in between the first mentioned group of segments. Therelationship of the two spiders is shown in Figure 1'7, the concentricring portions of the spiders being positioned within the recesses Ed inthe anode segments 78.

In the modification shown in Figure 18 the inner spider 52' may have itslegs 13' deformed or depressed as indicated so that they pass under thering portions of the outer spider T4.

In Figures 19 and 20 a still further form of strapping arrangement isdisclosed. The anode block may be made of a plurality of radiallyslotted sheet elements or laminations 80 as shown in Figure 20. Some ofthe sheet elements may be formed to provide recesses for receiving theradial legs 82 of the strapping member 8| which is in the form of aspider and the radial legs as of a similar spider 83, other sheetelements being formed to provide a recess 85 for the coaxial ring partsof the spiders as shown. Figure 19 shows the anode block with the toplamination of Figure 20 removed.

While we have indicated the preferred embodiments of our invention ofwhich we are now aware and have also indicated only one specificapplication for which our invention may be employed, it will be apparentthat our invention is by no means limited to the exact forms illustratedor the use indicated, but that many variations may be made in theparticular structure used and the purpose for which it is employedwithout departing from the scope of our invention as set forth in theappended claims.

What we claim as new is:

1. An electron discharge device including an anode block having acentral space and a plurality of radially directed slots extendingoutwardly from said central space and providing anode segments betweenadjacent slots, and a ring of conducting material having legs extendinginwardly therefrom to said central space and contacting alternate anodesegments, the inner ends of said legs forming continuations of the wallof said central space at said alternate segments.

2. An electron discharge device including an anode block having acentral space and a plurality of radially directed slots extending fromsaid space and providing a plurality of anode segments therebetween, anda pair of concentric spider elements of conducting material eachcomprising a ring having radially directed legs extending outwardlytherefrom, the legs of one of said spider elements contacting alternateanode segments, the other spider element having depressed portions toclear said one spider element, the legs of said other spider elementcontacting the remaining alternate anode segments.

3. An electron discharge device having an anode block, said anode blockhaving a central space and a plurality'of radially directed slotsextending therefrom and providing a plurality of anode segmentssurrounding said space, a cathode for supplying electrons within saidspace, said anode block having a recess at one end of and surroundingsaid central space, step members mounted on alternate anode segments insaid recess and adjacent said space, and a conducting ring mounted onsaid step members and connecting said alternate anode segments together.

4. An electron discharge device having an anode block, said anode blockhaving a central space and a plurality of radially directed slotsextending therefrom and providing a plurality of anode segmentssurrounding said space, a cathode for supplying electrons within saidspace, said anode block having a recess in one surface surrounding saidcentral space, step members mounted on alternate segments in said recessand adjacent said central space, step elements mounted on the otheralternate segments in said recess adjacent the outer periphery thereof,and a pair of concentric conducting rings, one of said conduct-ing ringsbeing mounted on and electrically connected to said step membersadjacent said central space, and the other conducting ring being mountedon and electrically connected to said step elements adjacent the outerperiphery of said recess.

5. The method of strapping the anode segments of a multi-segment anodecomprising the steps of forming an anode block with a central openingand a plurality of radially directed slots extending therefrom andproviding anode segments, re-

cessing one face of said block adjacent said central opening,positioning an annular spider having stepped legs registering withalternate segments within said recess adjacent said opening and on saidsegments, severing said spider along the sides of said slots andpositioning a conducting strapping ring on said stepped legs.

6. The method of strapping the anode segments of a multi-segment anodecomprising the steps of forming an anode block with a central openingand a plurality of radially directed slots extending therefrom andproviding anode segments, recessing one face of said block adjacent saidcentral opening and providing stepped elements on alternate segmentsadjacent the outer periphery of said recess, positioning an annularspider having stepped legs registering with the other alternate segmentswithin said recess adjacent said opening and on said segments, severingsaid spider along the sides of said slots, and positioning a firstconducting strapping ring on said stepped legs and a second conductingstrapping ring on said stepped elements for electrically connectingalternate anode segments together.

7. An electron discharge device including an anode block having acentral space and a plurality of radially directed slots extending fromsaid space and forming anode segments therebetween, said anode blockhaving a recess adjacent one end of and surrounding said central space,and a pair of concentric elements of conducting material mounted withinsaid recess, at least one of said elements comprising a ring havingradially directed legs extending therefrom and to alternate anodesegments, and means connecting the other element contacting theremaining alternate anode segments, said elements being supported out ofcontact with each other.

8. The method of strapping the anode segments of a multi-segment anodecomprising the steps of forming an anode block with a central openingand a plurality of radially directed slots extending therefrom andproviding anode segments, recessing one face of said block adjacent saidcentral opening, positioning an annular step member within said recessadjacent the outer periphery thereof and on said segments, removing theportions of said step member extending between alternate segments toprovide step elements on said alternate segments, positioning an annularspider having stepped legs registering with the other alternate segmentswithin said recess adjacent said opening and on said other alternatesegments, severing said spider along the sides of said slots, andpositioning a first conducting strapping ring on said step elements anda second conducting strapping ring on said stepped legs for electricallyconnecting alternate anode segments together.

JOHN S. DONAL, JR. CARMEN L. CUCCIA. BARREMORE B. BROWN.

REFERENCES CITED The following references are of file of this patent:

UNITED STATES PATENTS record in the

